1 137.8km. That’s how far British comedian Eddie Izzard ran over 27 days across South Africa. If you do the math, that breaks down to a marathon—41.8km—a day. Why would someone ever want to run 1 138km in 27 days, you may wonder. Well, he raised 1 million pounds  for British charity Sport Relief, a charity that raises money for vulnerable people in the UK and the world’s poorest countries. Also, 27 was not an arbitrary number. Izzard chose it to signify the 27 years Nelson Mandela was imprisoned before becoming president of South Africa.

Izzard’s feat was definitely not an easy one. He dealt with heat exhaustion, sun stroke, and dehydration, The Gaurdian reports. Things got so rough, in fact, that he had to take a rest day—and make up for it on the last day, running a double marathon—8 miles—on day 27, March 20th, 2016.

“It’s been the hardest thing I’ve ever done,” Izzard said in a video interview with the BBC immediately after finishing, “And I’m very tired. Thank you to everyone who’s donated. This was tough so don’t do this at home. I don’t think I can say much more.”

You can still donate to Izzard’s cause here. You can also check out these five sports and fitness charities to get involved with. Or, take up running yourself.